VOLUNTARY MOTION. 499 



cation of a stimulus, as readily as they do after apoplexy, and 

 after removal of the brain or division of their nerves. In torpid 

 brutes, after division of the nerves and removal of the brain, 

 cold and warmth destroy and restore the excitability of mus- 

 cles, as usual. The ligatures act immediately by depriving the 

 nerves of the power of stimulating them ; for a constant supply 

 of arterial blood is necessary to the functions of the nervous 

 system <i, and the ligature of the abdominal aorta, repeated by 

 Courten and Haller r , cuts off this from the lower part of the 

 spinal chord and what originate from it, the nerves of the 

 hind legs. s Another source of loss of motion must ultimately 

 arise, the loss of excitability and vitality from the want of cir- 

 culation in the muscle. 



In regard to its composition, muscle is said to be essentially 

 fibrine, but to contain also albumen, gelatine, lactic acid, fat, 

 salts, &c. and a substance termed osmazome, upon which 

 the peculiar taste and smell of soup depends, and which is a 

 yellowish brown substance, soluble in water and in alcohol hot or 

 cold, and not forming a jelly when concentrated. 



Raspail properly points out that muscle has thus been analysed 

 on the large scale, with its blood-vessels, lymphatics, nerves, and 

 fatty cellular membrane ; but that the analysis should have been 

 limited to the muscular cylinder. Gelatine is produced from 

 cellular texture, skin, tendons, ligaments, cartilages, and bones 

 by boiling only : osmazome by boiling from muscle, serum, and 

 mushrooms, and, according to him, is only an impure compound of 

 albumen and acetic acid: lactic acid he declares to be merely 

 acetic acid and albumen : and leucine, a white matter obtained 

 from muscle by Braconnot through the means of sulphuric acid, 

 to be only a mixture of oil, and even albumen rendered soluble 

 by an acid, with sulphite of ammonia. By repeatedly boiling 

 muscle, and holding it in the air between each boiling, Berthollet 

 found it at last acquire the smell and taste of old cheese. The 



q Le Gallois, Sur le Principe de la Vie. 



r W. Courten, Phil. Trans. No. 335. p. 500." 1678. 



" Haller, Comment. Soc. Sc. Gotting. t. iv. p. 293." 1754. 



* Sir Astley Cooper has just published the result of obstructing the vertebral 

 arteries which supply those parts of the spinal chord from which the nerves 

 chiefly concerned in respiration arise. Dyspnoea instantly ensued. (Guy's 

 Hospital Reports, No. iii. ) 



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